(CNN) - Deadly violence, ongoing tensions and the deliberate downing of a passenger airplane. Though that turbulence is happening far away from American streets - in Eastern Ukraine - why should Americans worry?

One reason: renewed fears of a return to Cold War relations between the United States and Russia.

Two powerful members of Congress spoke on the matter during separate interviews on CNN's "State of the Union."

Washington (CNN) – As thousands of unaccompanied children from Central America enter the U.S. along the southern border, Sen. John McCain believes any multi-pronged approach to the crisis must include two key elements: sending the children back to their home countries and securing the border.

"There has to be a halt to this … and the best way to do that is for planeloads of these young people to be returning to the country of origin and their families," the Arizona Republican told CNN chief political correspondent Candy Crowley on Sunday on CNN's "State of the Union."

Washington (CNN) - In the Republican-versus-Republican foreign policy feud between Rick Perry and Rand Paul, whose side does John McCain pick? The Arizona senator is not interested in stepping into the political crossfire. But that does not mean he won't offer a lecture.

"Sen. Paul is part of a wing of the party that's been there ever since, prior to World War 1, in our Republican Party. And that is a withdrawal to fortress America," McCain told CNN Chief Political Correspondent Candy Crowley on CNN's "State of the Union" on Sunday. "I do believe that the things we're seeing in the world today - in greater turmoil than any time in my lifetime - is a direct result of an absence of American leadership.

Washington (CNN) – Sen. John McCain said Sunday the violence roiling the Middle East has likely never been worse, as rockets fall in Israel and Gaza, residents flee, warning sirens blare and the death toll rises.

"I would argue that given conditions in the Middle East, this might be more dangerous than any time in the past," the Arizona Republican told CNN chief political correspondent Candy Crowley on CNN's "State of the Union." "Not only conditions domestically, within Israel, but also the fact that Egypt is really not playing the role they traditionally have, countries like Qatar and others that could play a role."

Washington (CNN) - If you're a national political party salivating over the prospect of winning a seat that's long been in your opponent's hands, what should you do?

One strategy: give your candidate a huge megaphone.

Enter the Republican National Committee, Iowa GOP Senate nominee Joni Ernst - and an address heard by millions around the country.

On Saturday, Ernst delivered the weekly Republican address. The candidate pushed familiar conservative themes: smaller government, opposition to Obamacare and strong national security. Ernst also played up her outsider status and pushed populist themes.

Washington (CNN) – Is a law designed to protect children from human trafficking actually causing a humanitarian crisis along the U.S. southern border, allowing thousands of children to illegally surge into the United States?

Amid the crisis and calls to change the law, one of its chief backers defends it.